Anyone who studies the matter will reach the conclusion that good marksmanship, per se, is not the key to successful gunfighting. The marksmanship problem posed in a streetfight is ordinarily pretty elementary. What is necessary, however, is the absolute assurance on the part of the shooter that he can hit what he is shooting at – absolutely without fail. Being a good shot tends to build up this confidence in the individual. Additionally, the good shot knows what is necessary on his part to obtain hits, and when the red flag flies, the concentration which he knows is necessary pushes all extraneous thinking out of his mind. He cannot let side issues such as fitness reports, political rectitude, or legal liability enter his mind. Such considerations may be heeded before the decision to make the shot is taken, and reconsidered after the ball is over; but at the time, the imperative front sight, surprise break must prevail.
Thus we have the paradox that while you almost never need to be a good shot to win a gunfight, the fact that you are a good shot may be what is necessary for you to hold the right thoughts – to the exclusion of all others – and save your life. This may come as a shock to a good many marksmanship instructors, but I have studied the matter at length and in depth, and I am satisfied with my conclusions.
From Jeff Cooper’s Commentaries
Vol. 5, No. 1